Power-driven typewriting machine



Nov. 3, 1936. A. SALZBERGER ET AL 2,959,537

POWER DRIVEN TYPEWRITIMG MACHINE Filed Aug. 19, 1935 2 Sheets-Sheet l lrwenfbr A7762! eas J's: zzierycr 122i RLICAQI'J Baum 1/2877 Nov. 3, 1936.,

A. SALZBERGER ET AL 2,@59,537

POWER DRIVEN TYPEWRITIMG MACHINE Filed Aug. 19, 1935 2 sheets-sheet 2 m I? Q a Q Inventor" A'ncl'l-eas JaZze r96 and Rickard Baumgzrle 7L Patented Nov. 3, 1936 POWER-DRIVEN TYPEWRITING MACHINE Andreas Salzberger and Richard Baumgarten,

Erfurt, Germany, assi'gnors to Europa SchreIbmaschinen A. G., Erfurt, Germany Application August 19, 1935, Serial No. 36,894 In Germany April 13, 1933 11 Claims.

The object of the present invention is to present a power-driven, noise-dampened type-lever writing machine, the type-levers of which are lifted by being coupled witha rotating shaft.

There are already known power-driven typelever writing machines, in which the type-levers are lifted, and pressed against the paper roller, by means of rotating eccentric disks which can be coupled with the type-lever rods, but in these known machines neither a sufiicient sling-force of the type-levers is obtained, nor is the pressure produced by the types at the imprint place sufiicient to eifect the required noise-dampened imprint.

There exist also power-driven writing machines, in which the type-levers lifted manually in the usual manner by a depression of the keys are intercepted by a catching device producing an imprint on the paper by the intermediary of a power-driven eccentric. Also push-rod writing machines have become known, the types of which are intercepted in a similar manner and are thrown against the paper roller at the lower portion of the same. In both cases the power-drive is, however, thrown into gear by the type-carrier only when the type-lever touches or shortly before it touches the catching device. Apart from the longer key stroke required by this manner of operation, and from the greater expenditure of hand-power required for throwing the power drive into gear, much time gets lost by the retarded coupling-in, the masses are not quickly enough accelerated and no increased writing speed can be attained.

The object of the present invention is to overcome the above-mentioned drawbacks and to obtain, simultaneously with full utilization of the source of power for the entire type-lever stroke, a noise-dampened imprint, as well as a continuous speed-movement of the type-levers, these efiects being obtained by the provision of a pressing-on device arranged near to the writing place of the paper roll, in front of the same rotating during the entire type-lever movement, and being in a corresponding positive driving connection with the coupling shaft, that pressing-on device taking hold of the type-lever at the end of its stroke and pressing it against the paper roller. As pressing-on device or member especially a rotating cam is employed which presses against the type-lever possibly near to the imprint place, viz. at the head of the type.

be coupled, the pressing-on cam receiving the type-lever from said driving member in the proximity of the upper dead-centre position of the eccentric, the number of teeth of the shaft corresponding to the number of revolutions of the pressing-on cam.

By means of the eccentric motion it is not necessary to transmit any appreciable power. The entire type driving and feeding rods can be easily made and permits increased speeds owing to the slight masses, whereas the pressing-on gearing with its smaller and merely rotating members can have larger dimensions without any drawback resulting therefrom.

Provision is also made that the engagement of the catch-pawl with the eccentric disk, as Well as the disengagement of these members, takes place noise-damped, without a hard impact.

The invention is illustrated diagrammatically and by way of example on the accompanying drawings, on which Figure 1 is a transverse section through a power-driven type-lever writing machine designed according to this invention, the typelevers being shown in their position of rest.

Figure 2 is a similar representation, the keylever being, however, depressed and the typelevers being lifted up to the cam.

Figure 3 is a side-view of a type-lever head in lifted position, at the place of entrance into the cam.

Figure 4 is a similar view, the type-lever head being pressed against the paper roller by the cam, and

Figure 5 is a front view of the cam with the type-lever head in operated state.

On the drawings, i denotes the paper roller and 2 is the pressing-on cam for the type-levers. This cam consists of two individual disks 2* attached t the inner end of two shafts 3 which extend from both sides to the middle of the ma chine. The outer ends of the shafts 3 are equipped with screw-wheels meshing with similar screw wheels t secured to a connecting axle transmitting the power from the source of power (not shown). On the drawings said wheels have, for the sake of greater distinctness, been drawn as bevel-wheels. The lower connection between the axle 5 and the continuously rotating shaft 8 of the power drive consists likewise of screwwheels also omitted in the drawings.

The type-levers 6 are below the type head provided on both sides with projections l constituted,

for instance, by bolts or by small rolls, and each cam-disk 2a has at its inner side a curved groove into which the respective projection 1 can enter and by which the appertaining type is pressed against the paper roller in order to produce an imprint.

The driving power is transmitted by a toothed shaft 8, and the number of revolutions and the adjustment of the cam 2 is so chosen that every tooth of the shaft 8 corresponds to one revolution of the cam 2 so that a type-lever lifted up to the cam meets always the entrance end of the curved grooves. In order to accelerate the reverse motion of the type-levers 6, said grooves terminate at sling cams 2 whereas the oppositely located side of the groove wall is well rounded off to obtain a quick exit of the roll I out of said groove. The strength of the imprint can be varied by appropriate adjustment of the paper roller.

In order to allow of lifting the type-lever possibly sling-free up to the cam 2, safety members constituted by springs l2 and l3 acting counter to the direction of lifting are provided at the members 9 and Ill serving for moving the typelevers. The lifting motion proper is produced gradually by means of an eccentric disk l8 by the intermediary of the two double-armed levers 9 and lil supported by pivots l5 and IS in the frame l4 of the machine. The lever 9 engages by means of a bolt 38 in known manner the slot 6 of the type-lever, and has in its lower leg a slot 9 which receives the bolt ll of the lever ID, the other leg of this lever carrying a roll N that contacts with the rotating eccentric disk l3.

In Fig. 1 the lever I0 is shown with its roll H in contact with the eccentric, the latter being in its position of rest. The bolt 38 does not impact to the end of the slot 6, but, in order to obviate noise, the back of the lever 9 contacts with a soft piece 39 similar to the soft supporting piece 48 provided for supporting the type-levers.

The eccentric disk I8 is designed as a coupling disk for connecting with the toothed shaft 8, in that it is provided with a pawl l9 pivoted about the pin 20. The tooth of the pawl is continually drawn into the toothing of the shaft 8 by means of a tensile spring 31. The pawl l 9 is prolongated beyond its fulcrum for the purpose of uncoupling, and is provided with a rectangular extension l9 serving as end-abutment for the revolution of the disk I8. Said prolongation forms on its back or outer side an elevation which when the members concerned are disengaged, as in Fig. 1, corresponds about with a part of a circle having the axis of the toothed shaft as its centre, whereas when the members concerned are in their opera tive position, as in Fig. 2, a member entering into the path of the back is opposed by a rising curve.

At the part M of the frame of the machine is located on a pivot 22 a double lever 2| which is turnable in the direction of motion of the eccentric disk l8; one of the legs of said lever embraces the eccentric and carries a roll 23 located in the path of the eccentric I8, whereas the other leg extends upwards and has a nose 2| that can be turned into the path of the pawl l9. When said nose is in this position (Fig. 1) it contacts with the back of this pawl and depresses it whereby the tooth of the pawl is disengaged from the toothing of the shaft 8. The lever 2| is maintained in this position by a ratchet-pawl 24 which is likewise supported at the part I4 of the frame and is subject to the action of a spring 4| and assumes, under this action, a position in front of the downwardly directed lug 2| of the double-' lever 2|.

The position of rest of the parts described is released by the key lever 25 which is supported on a pivot 25 at the frame l4 of the machine and to which is pivoted a trigger-pawl 26 having a nose 26 taking over a lug of the ratchet-pawl nose 24.

When the key-lever 25 is depressed, the nose 26 pulls theratchet-pawl 24 downwardly with it until a horizontal leg 26 of the trigger pawl 26 pushes upon an adjustable abutment member 28 attached to the comb-shaped guide member 21, counter to the action of a spring 29, whereby the vertical leg of the nose- 26 is stripped off from the ratchet-pawl 24. The position of these members with respect to one' another is then that shown in Fig. 2. On the return movement of the key-lever 25 the trigger pawl 26 is again moved into its original position, i. e. its position of rest, by said spring 29 in which position it contacts with an abutment pin 42.

In the meantime the ratchet pawl 24 has been drawn oif downwardly, together with its nose, from the downwardly directed nose 2| of the double-lever 2| by the downward movement of the pawl 23. The vertical leg of the doublelever 2| is provided, besides with the nose 2| for the end abutment, with an eye 2| and a lug 2|. In front thereof, at the part M of the frame, is screwed to this part a guide member 30 of sheet-metal, an abutment member 3| likewise of sheet-metal, and a member 32 provided with an ear. To this ear and to the ear ill of the double-lever 2| is attached a tensile spring 33 which draws said lever forwardly so as to bring the nose 2| into contact with the edge of the abutment sheet-metal member 3|. The sheet-metal guide member 30 is provided on that side where there is the toothed shaft with a rectangularly bent-off portion 30 which only loosely contacts with the frontal side of the lug |9, in such a manner, that when the end-abutment 2 I is being lifted the pawl I9 is slightly pressed against the face of the lug H by the action of the spring 31. The pawl cannot, therefore, engage the shaft 8 at once and cannot, thus, be torn by an early action of the toothed shaft against the not yet completely removed end abutment member 2|.

Initiating the rotary movement of the eccentric is effected in a soft and gradual manner by means of a small brake block 34 which continually slides in a groove of the toothed shaft under the action of a pressure-lever 35 and a tensile spring 36 which two members are attached to the eccentric disk. The pressure to which said small block is subjected, or the frictional force respectively, is so chosen that only shortly after the abutment 2| has left that position in which it could act as abutment, the toothed shaft 8 has taken the disk l8 along with it so far that the pawl |9 fully engages its mate and is now taken round by the toothing with the usual speed of this shaft.

Also if the key lever is held depressed for a longer period of time, the eccentric disk should not perform more than one rotation. It has, for this reason, been provided that the uncoupling of the drive is every time effected by making the eccentric disk |8 contact with the roll 23. The long arm of the lever 2| is then depressed, the rear of the nose 2| slides over the 'back of the nose 24, the ratchet lever 24 gives way downwardly and finally the nose 24 jumps so as to arrive in front of the nose 2 I and holds the double-lever 2| and, thus, also the end abut,

ment member 2| fast in its locking position, as in Fig. 1.

Mention must be made of the feature that also the stopping of the eccentric disk I8 is not effected by a hard impact of the lug 2| of the double-lever at the bent-off portion IQ of the pawl. In fact, prior thereto the lug 2| touches slightly the exterior curved back of the pawl in the proximity of the pivot 20, and this curve is so shaped that the pawl is forced out of the toothing of the shaft 8 already about in the middle portion of the pawl prolongation so that the impact in the end position is effected only by said pawl being taken along by reason of the braking action exerted by the small block 34.

We claim:---

1. A mechanism for obtaining noise-dampened imprints of the type-levers of a powerdriven type writing machine comprising in combination with the type-levers a power-driven rotating device adapted to lift the selected typelever, a paper-roller against which said levers are pressed, and means arranged before said rotating device, adapted to take hold of the type-lever just being actuated at the end of its stroke and to press it against said roller, said means rotating continually during the entire type-lever movement and being in positive operative connection with the power-driven rotating device.

2. A mechanism as specified in.. claim 1, in which the said means is constituted by a rotary cam pressing upon the type-lever near to the place of writing.

3. A mechanism as specified in claim 1, in which said means is constituted by a rotary cam pressing upon the type-lever near to the writing place and comprising two rotary cam disks rotating parallel to the path of the type-lever and in which lateral projections at both sides of the typelever at the upper end of the same are provided adapted to engage said cam discs.

4. A mechanism as specified in claim 1, in which said means is constituted by a rotary cam pressing upon the type-lever near to the writing place and comprising two rotary cam disks rotating parallel to the path of the type-lever and in which lateral projections at both sides of the type-lever at the upper end of the same are provided adapted to engage said cam discs, said cam discs having each a curve adapted to draw the type-lever forwardly against the paper roller and another curve adapted to sling it rearwardly.

5. A mechanism as specified in claim 1, in which said means is constituted by a rotary cam pressing upon the type-lever near to the place of writing, and in which the type-lever lifting device is constituted by a toothed shaft and an eccentric disk adapted to be coupled with said shaft, the toothing of said shaft comprising as manyteeth as said cam performs revolutions during one revolution of the shaft.

6. A mechanism as specified in claim 1, in which said means is constituted by a rotary cam pressing upon the type-lever near to the place of writing, and in which the type-lever lifting device is constituted by a toothed shaft and. an eccentric disc adapted to be coupled with said shaft, the toothing of said shaft comprising as many teeth as said cam performs revolutions during one revolution of the shaft, said rotary cam and disc being so timed that the rotary cam seizes the type-lever when the eccentric disc is in the proximity of its upper dead-centre position.

7. A mechanism as specified in claim 1, in which the type-lever lifting device comprises a toothed shaft, an eccentric disc and means adapted to couple said shaft with said disc and comprising a pawl attached to the lifting disc and adapted to engage the toothing of said shaft and adapted to engage the toothing of said shaft and a stationary abutment member acting upon said pawl, said pawl and abutment member being so devised that said pawl is prevented from engaging the toothing of the toothed shaft until the rotary motion of the disc has been initiated and braking means arranged on said disk being in frictional engagement with the shaft and taking the disc along with the shaft to initiate its rotary motion.

9. A mechanism as specified in claim 1, in which the type-lever lifting device comprises a toothed shaft, an eccentric disc and means adapted to couple said shaft with said disc and comprising a pawl attached to the lifting disc and adapted to engage the toothing of said shaft and a stationary abutment member acting upon said pawl, a nose forming a part of said abutment member and a curved back on said pawl adapted to be engaged by said nose when entering into the path of said pawl and tollift, prior to the eccentric disc arriving in its end-position, said pawl out of the toothed shaft and braking means arranged on said disc being in frictional engagement with the shaft and adapted to turn the eccentric disc into its end-position.

10. A mechanism as specified in claim 1 in which said type-lever lifting rotating device is constituted by a toothed shaft and an eccentric disc adapted to be coupled with said shaft and in which a pawl is provided attached to the eccentric disk and adapted to engage the teeth of the shaft and means are provided for controlling said device consisting of a member hinged to the frame of the writing-machine and lying on the one hand in the path of the eccentric disc and on the other handin the path of the pawl and being adapted to be engaged by said' disc and to be brought into locked checking position by it at the end of each revolution.

11. A mechanism as specified in claim 1, in

which said type-lever lifting rotating device is constituted by a toothed shaft and an eccentric disc adapted to be coupled with said shaft and in which a pawl is provided attached to the eccentric disk and adapted to engage the teeth of the shaft and means are provided for controlling said device consisting of a member hinged to the frame of the writing-machine and lying on the one hand in the path of the eccentric disc and on the other hand in the path of the pawl and being adapted to be engaged by said disc and to be brought into locked checking position by it at the end of each revolution, a key level, a second pawl hinged to the key-lever and having a nose; a third pawl adapted to engage said nose and to lock the said member and an adjustable abutment 'member provided at the frame of the machine and adapted to turn the second pawl into its disengaging position when'the key-lever is depressed, whereby also the third pawl is disengaged.

ANDREAS SALZBERGER. RICHARD BAUMGARTEN. 

